Along with the continuous development in the industry of power supply sockets with leakage protective functions (also known as GFCI), even higher requirements are proposed for their functions as well as service safety, especially for the power supply sockets/plugs to be exported to the USA.
Currently, the power sockets/plugs exported to the USA all have life termination detection and indication functions. The most commonly adopted leakage detection protection circuit that is installed in a power supply plug/socket/switch circuit interrupter with leakage protective function is provided with at least one switch linked with a reset button and provided beneath the reset button. At the moment when the reset button is pressed down, this switch is closed, generating an analog leakage current to detect whether the life of the leakage detection protection circuit has terminated. This creates the need to design an analog leakage current generation circuit, which includes the switch, to generate an analog leakage current and to automatically detect whether the life of the leakage detection protection circuit has terminated. This design increases the complexity of the leakage detection protection circuit.
Also, normally the leakage detection protection circuit has been designed with a circuit that can detect whether the life of the leakage detection protection circuit has terminated by pressing a test button to manually generate an analog leakage current.